Presentation is loading. Please wait.

Presentation is loading. Please wait.

but loss of consolidation

Similar presentations


Presentation on theme: "but loss of consolidation"— Presentation transcript:

1 but loss of consolidation
STM LTM Retrieval STM LTM STM LTM Storage; Consolidation Case of H. M. Hippocampus Not loss of LTM, Not loss of STM, but loss of consolidation

2 Tolman: Cognitive Maps
St G

3 How? Intramaze (e.g., smell food, scratch on floor)
Olton: Radial Arm Maze How? Intramaze (e.g., smell food, scratch on floor) Extramaze (stimuli around the maze)

4 Choose 4 Then rotate maze * * * *

5 Which will they visit? Go to “space”, not arm Use extramaze cues * * * *

6 Morris: Water Maze Hence: “Spatial”, and not any single cue.

7 Morris: Water Maze Further tests: Probe trial

8 Role of Hippocampus in Spatial Learning
Hippocampal Damage: Still get a little faster at finding platform Probe Trial: Shows no “spatial strategy

9 Role of Hippocampus in Spatial Learning
If visible platform, do as well as normal Suggests role of hippocampus specifically in the “spatial” aspects of the water maze task

10 Configural Learning Hypothesis
Spatial Learning is type of configural learning: response is based on > 1 cue Hippocampus and Configural learning: If Hippocampal damage, can do: discrimination, but not configual A—US B—US AB— A—US B—

11 Integrating across experiences
Rule learning (learning set) Strategies Win-stay Win-shift Strategy is then applied to new situations: More rapid learning of new (same strategy) task.

12 Hypothesis Testing New task: Try different hypotheses (strategies) If wrong, throw it out If correct, stick with it Leads to “step function” learning curves looks like “insight” Percent Correct Trials 100

13 Concept Formation Concept: Category- a set of objects/events having common features/relationships Abstraction: How a concept is formed Abstract (summarize) common features. Form prototype (composite average) based on experiences with specific exemplars (examples)

14 “Neural networks” and prototype formation
Common assumptions: 1. Universal connectivity (note: preparedness: perhaps not “universal”) 2. Contiguity 3. Spread of activation

15 “Neural networks” and prototype formation
Common assumptions: 1. Universal connectivity 2. Contiguity 3. Spread of activation 4 legs ears tail fur

16 Learning rule: Delta Rule
4 legs ears tail External input fur Internal input

17 Learning rule: Delta Rule
Sensory neuron Sensory neuron External input T E Internal input ∆ synaptic efficacy ∆ Int = c (Ext - Int) REM: ∆V = c (Vmax - V)

18 Get Expect Similar Ideas External Internal Vmax V Sensory detection
and activation Retrieval of a node Difference = Surprise


Download ppt "but loss of consolidation"

Similar presentations


Ads by Google